Predicting compliance with a regimen of digoxin therapy in family practice.

The ability of family physicians to predict patients' compliance with a regimen of digoxin therapy was studied by an analytic survey. Compliance was assessed by a pill count at a home visit and measurement of the serum digoxin level in a blood sample obtained at that visit. Of 74 patients 70% were found to be taking more than 80% of their pills and 86% had a therapeutic serum digoxin level. The 10 physicians were unable to predict compliance better than chance, even for the 58 patients they had known for 5 or more years. Physicians should be cautious in predicting compliance, and when they prescribe oral digoxin therapy they should monitor the patient's compliance by means of the serum digoxin levels.